No single hypothesis or theory has been widely accepted for explaining the functional mechanism of global alpine/arctic treeline formation. The present study tested whether the alpine treeline is determined by (1) the needle nitrogen content associated with photosynthesis (carbon gain); (2) a sufficient source-sink ratio of carbon; or (3) a sufficient C-N ratio. Nitrogen does not limit the growth and development of trees studied at the Himalayan treelines. Levels of non-structural carbohydrates (NSC) in trees were speciesspecific and site-dependent; therefore, the treeline cases studied did not show consistent evidence of source/carbon limitation or sink/growth limitation in treeline trees. However, results of the combined three treelines showed that the treeline trees may suffer from a winter carbon shortage. The source capacity and the sink capacity of a tree influence its tissue NSC concentrations and the carbon balance; therefore, we suggest that the persistence and development of treeline trees in a harsh alpine environment may require a minimum level of the total NSC concentration, a sufficiently high sugar:starch ratio, and a balanced carbon source-sink relationship.

National parks throughout the world are increasingly challenged to accommodate the dual mandates of protecting natural and cultural resources while providing positive recreation experiences for park visitors. This is particularly true for China's national forest parks (NFPs), now important destinations for both the domestic and international tourist markets. The sustainable management of the NFPs requires an understanding of park visitors' attitudes. This paper examines how visitors perceive the roles and functions, policies and appropriate uses relating to China's NFPs, based on data from an important NFP. Results suggest that visitors' attitudes towards NFPs are positive. The majority of study participants placed higher priority on the protection of the ecological integrity of NFPs than on their development and use for recreation and tourism. They were supportive of NFP policies for limiting visitor numbers and phasing out inappropriate uses. Non-consumptive activities were viewed as highly appropriate while religious activities and dancing/karaoke lounges were seen as highly inappropriate. Visitors who placed higher priority on the protection of ecological integrity were less likely to compromise protection with use, and more likely to support non-consumptive activities. Future research needs are discussed.

No abstract

No abstract

Nature-based tourism is a global phenomenon, with traditional forms of use of natural areas, such as wood harvesting and agriculture, paving the way for ecotourism. However, there has been limited exploration of the role of institutions in driving this transition. Consequently, this paper sought to explore the role of institutions in producing space for tourism within National Forest Parks (NFPs) in China. To achieve this objective 68 nationallevel policy documents from 1949 to 2014 were collected and analyzed. Findings demonstrate a transformation in the role of NFPs, orchestrated by the state, capital and society for tourism. In particular, NFPs, as an ideological space in national development, were not only an outcome of economic, social, political, and ecological processes, but also balanced the power between the state, capital and society. Institutional changes mirrored the dynamic relationship between the state, capital and society in China. Future research should focus on the role of institutions in producing space for tourism for and within parks at the local level, especially in developing contexts.